998-00-5Relevant articles and documents
1H NMR study of the catalytic system (rac-Me2Si(2-Me, 4-PhInd)2ZrCl2- polymethylalumoxane)-triisobutylaluminum
Faingol'd,Chukanova,Bravaya
, p. 957 - 963 (2005)
The products of the reactions of polymethylalumoxane (MAO) with triisobutylaluminum (TIBA), rac-Me2Si(2-Me,4-PhInd) 2ZrCl2 (1) with MAO (1 + MAO), and (1 + MAO) + TIBA were studied by 1H NMR at different molar ratios of the components. When the ratio AlTIBA/AlMAO is ～6, the reaction between MAO and TIBA involves the replacement of the methyl group of MAO by isobutyl groups and the formation of isobutylmethylalumoxane or mixed isobutylmethylalumoxane structures. When the TIBA content in the system increases to 30 mol.%, these structures are rearranged to form products with a low degree of association. With the equimolar ratio of the reactants, the main reaction products are tetraisobutylalumoxane and polyisobutylalumoxane. The 1 + MAO system with the molar ratio AlMAO/Zr = 50 affords a MAO-bonded monomethyl monochloride derivative [L2ZrCl-μ-Me]δ+[MAO] δ-. An increase in this ratio to 150 produces intermediate binuclear complexes [L2ZrCl-μ-Me-MeZrL2] +[MAO]- and [Me2Al-(μ-Me) 2-ZrL2]+[MAO]-. The addition of TIBA induces the replacement of the ZrMe groups by isobutyl groups at the first step of the interaction and formation of nonidentified reaction products at the subsequent steps.
Dehydration of LnCl3·6H2O (Ln=Tb, Nd, Dy) in the reaction with i-Bu3Al, Et3Al, Et2AlCl, EtAlCl2 and formation of the complexes LnCl3·3(BuO)3PO
Bulgakov, Ramil G.,Kuleshov, Sergei P.,Zuzlov, Aleksei N.,Mullagaleev, Ildar R.,Khalilov, Leonard M.,Dzhemilev, Usein M.
, p. 56 - 62 (2007/10/03)
The dehydration of toluene insoluble salts TbCl3·6H2O (1), DyCl3·6H2O (2) and NdCl3·6H2O (3) in their reaction with organoaluminum compounds (RnAlX3-n): i-Bu3Al, Et3Al, Et2AlCl, EtAlCl2 and the influence of (BuO)3PO (TBP) on the process were studied. In the reaction of RnAlX3-n with the water of crystallization of salts 1-3, aluminoxanes and the following gases are formed: i-BuH for i-Bu3Al, EtH for Et3Al, EtH and HCl for Et2AlCl and EtAlCl2 as a result of the attack on the Al-C or Al-Cl bond independent of the presence of TBP. In the absence of TBP the salts 1-3 are dehydrated by RnAlX3-n to give insoluble products LnCl3·0.5H2O·0.5(R2Al) 2O, where R is alkyl for i-Bu3Al and Et3Al, or R is alkyl and Cl for Et2AlCl. The reaction of RnAlX3-n with 1-3 in the mixture of toluene-TBP at the ratio TBP/Ln≥12:1 results in the complete removal of water from LnCl3·6H2O and leads to the formation of homogeneous solutions, containing aluminoxanes and LnCl3·3TBP complexes. Homogeneous solutions, obtained after interaction in the system NdCl3·6H2O+TBP+PhMe+R3Al were then activated with either i-Bu3Al or (i-Bu2Al)2O and used as catalysts for polymerization of butadiene. All the catalysts were highly active for polymerization of butadiene, and produced a low-molecular polybutadiene.
